Yes I think it's much easier to explain that method of finding the hex file to people. I work on 2 different bootloaders(ariadne and avr_boot) that require the user to find the hex file so this could simplify the documentation. Unfortunately I discovered a bug this week: the hex file name is the variant appended to the sketch name so if you have a board that references another vendor's variant(e.g. arduino:standard) then that causes an error on Windows because the : is not a valid character in filenames. I reported it and it has already been fixed but is only available in Arduino IDE 1.6.6.